1. Field of the Invention
The present invention relates generally to a mileage display system for a vehicle which is capable of displaying an accumulated distance traveled by a vehicle, or an accumulated mileage, using a predetermined number of display digits on a display. More particularly, the present invention relates to a mileage display system for displaying the accumulated mileage by accumulating a pulse signal generated according to running of the vehicle.
2. Description of the Background Art
Electronic mileage display systems have a maximum display value that is established by the predetermined number of display digits. Conventionally, a mileage display system for a vehicle automatically restarts from zero when the mileage overflows by exceeding the maximum display value. In such instances, accurate mileage is thus unknown. This is inconvenient when evaluating a used vehicle for purchase, or when determining appropriate timing of parts replacement and or other maintenance matters.
The mileage display system commonly found in motorcycles has a fewer number of display digits than that found in four-wheel motor vehicles. For example, only five digits are displayed. If the motorcycles are heavily used, however, a mileage display overflow can occur. In some countries, motorcycles are used for business purposes such as providing bike taxies and may also be used for other special purposes. In such cases, the mileage display overflow is more likely to occur. Nonetheless, such applications of the motorcycles account for a very small percentage of the total number of motorcycles in operation. It is therefore highly unreasonable to modify the display by increasing the number of displayed digits of the accumulated mileage.
In view of the foregoing, an accumulating device or an integrator is proposed for use in mileage displays. Such a device is disclosed in Japanese Patent Laid-open No. Hei 11-118509. In Japanese Patent Laid-open No. Hei 11-118509, the integrator operates on either one of the following modes: specifically, a first integration mode, in which, when an overflow occurs, subsequent integration is suspended; and a second integration mode, in which, when an overflow occurs, only low-order digits of the mileage are displayed, flashing off and on.
In the first integration mode of the integrator described in Japanese Patent Laid-open No. Hei 11-118509, a function as the mileage display system is lost in order to suspend integration following the overflow. In the second integration mode, the low-order digits of the mileage are displayed, continuously flashing off and on. This makes the display unnecessarily prominent, thus obstructing a view of a rider. In addition, the simple blink display does not provide the number of overflows that have so far occurred.
In view of the foregoing problems in the conventional art, the object of the present invention is to provide a mileage display system which, after the mileage overflows by exceeding the maximum display value as established by a predetermined number of display digits, is capable of simply displaying an accurate, accumulated distance traveled or accumulated mileage.